An understanding of the fundamental correlation between grain size and
material damping is crucial for the successful development of structural
components offering high strength and good mechanical energy absorption.
With this regard, we fabricated aluminum sheets with grain sizes ranging
from tens of microns down to 60 nm and investigated their tensile
properties and mechanical damping behavior. An obvious transition of the
damping mechanism was observed at nanoscale grain sizes, and the
underlying causes by grain boundaries were interpreted.